U.S. Pat. No. 4,061,683 describes compounds of general formula: ##STR3## in which R.sub.1 is hydrogen, halogen, alkyl, vinyl or ethynyl;
R.sub.2 is hydrogen, halogen, methyl or ethyl; PA0 R.sub.3 is hydrogen, methyl or alkoxyl; PA0 R.sub.4 is hydrogen, halogen or methyl; PA0 R.sub.5 is hydrogen or R.sub.3 and R.sub.5 form a carbon-carbon bond or an oxygen bridge; PA0 R.sub.6 is hydrogen or methyl; PA0 R.sub.7 is cyclohexyl or a variously substituted phenyl group; PA0 Y is either a methylene or an oxymethylene bridge; and PA0 m and n are either 0 or 1, PA0 Z represents oxygen or sulphur; PA0 R.sub.1 represents a substituted phenyl group; PA0 R.sub.2 represents hydrogen, methyl or ethyl; and PA0 R.sub.3 and R.sub.4 each represents hydrogen, methyl, ethyl, methoxy, ethoxy, nitro or halogen.
as showing insecticide activity against Orthoptera, Isoptera, Hemiptera, Coleoptera, Lepidoptera, Diptera and Acarina.
Among other compounds (col. 17, No. 30 and col. 19, No. 46) the compound ##STR4## is disclosed.
In U.S. Pat. No. 4,153,731, there are disclosed compounds of the general formula: ##STR5## in which n is 0 or 1;
Such compounds are described as able to control a large number of insects, including Acarididae, Tenebrionidae, etc.
U.S. Pat. No. 4,000,312 and U.S. Pat. No. 4,140,794 describe aliphatic compounds having juvenile hormonal activity and a dichloro- or trichloro-substituted end vinyl group bound to a phenyl or substituted phenyl group. Among them, only those having a trichloromethyl terminal group exhibit acaricidal activity.
As to ants, and as is known, the noxious species of ants diffused in all parts of the world are quite numerous and the damages they inflict are found in various fields. For instance, in the agricultural field they may prove harmful both by attacking cultivations or foodstuffs, as well as by rendering the fields intended for cultivations or as pastures unusable.
Other kinds of equally heavy damages will be found in the civil area, because of attacks on wooden buildings and structures, and in the veterinary and medical areas by bites and punctures to cattle as well as humans.
The ant species considered most noxious belong mainly to the following genera: Pheidale, Aphaenogaster, Messar, Oecophylla, Macronischoide, Camponotus, Crematogaster, Iridomyrnex, Atta, Acromyrnex and Solenopsis.
One of the sectors in which there have recently been observed ever-increasing damages and considerable difficulties in controlling such infestations is that of the infestations by ants of the Solenopsis genus in a number of southern states in the United States of America.
It has been calculated that, in the USA, the ants of the Solenopsis genus (called "fire-ants") infest with their ant hills (nests), up to 250 per hectare, and render unusable fields having a total surface of about 80 millions of hectares.
To this type of damages there must be added the losses in cattle killed by the poisonous bite of these insects as well as the serious danger for people living in the neighborhood of infested places or for people frequenting such places.
As a matter of fact, there have been reported quite a number of cases where people had been attacked by such ants and had then died because of a highly sensitivity to the poison injected by their bite.
Earlier, the fight against Solenopsis ants in the USA was carried out using a compound called Mirex, a polycyclic perchlorinated hydrocarbon.
In spite of the good results obtained with that compound, the same was banned when it was discovered that it left residues in human milk and when it was evidenced that it is cancerogenous and teratogenous. Therefore, because of the still growing diffusion of the infestation, it is necessary to find new active products that, at the same time, are harmless for humans and for the environment.
In Belgian Pat. No. 877,164, assigned to Montedison S.p.A., there are described a number of compounds endowed with a juvenile hormonic activity on noxious insects and thus usable in the agrarian and domestic spheres in the fight against insect infestations.